Limestone pavements are one of the most stunning features of limestone country and are particularly well-developed on Great Asby Scar and the surrounding areas of Knott, Grange Scar and Little Asby Scar. These exposed areas of bare limestone are divided into blocks or ‘clints’ and fissures or ‘grykes’. The pavement surfaces represent bed surfaces and the grykes form along existing vertical cracks, known as joints. One area of Great Asby Scar with large smooth clints is known as Shining Stones because of the way it gleams on a wet day when viewed from a distance. Clint surfaces may display a range of features produced by solution. These beautiful runnels, grooves and hollows are known collectively by the German word ‘karren’. Most of the area’s pavements are developed on Knipe Scar Limestone, but some also occur on Potts Beck Limestone and Ashfell Limestone.
The main features of limestone pavement. © E. Pickett
The iconic karst landscape of Great Asby Scar, characterised by expanses of limestone pavement. © S. Woodhead
Limestone pavement near Castle Folds, Great Asby Scar. The Knipe Scar Limestone here is gently folded. © D. Evans
Close-up of clints in sloping limestone pavement near Castle Folds, Great Asby Scar, showing downslope development of runnels. © E. Pickett
A traditional interpretation of limestone pavements is that they represent beds scraped clean by ice, which were then affected by solution processes. Some features have undoubtedly formed since glaciation, possibly below a cover of glacial deposits, wind-blown silt, soil and vegetation, which has largely disappeared. However, it is now recognised that pavements have complex origins and have formed over much longer time periods, with some features possibly dating back to Carboniferous times.
Limestone pavement on Little Asby Scar, showing runnelled clints and grykes, with the Howgills in the distance. © E. Pickett
Limestone pavement on Little Kinmond, Great Asby Scar, showing wide grassy grykes. © E. Pickett